1. PURPOSE : The purpose of generating this Method Statement is to define the procedure step by step to implement the correct practices for welding at project site.
2. SCOPE : This Method Statement refers to various work procedures contained within project control documents, which explains and covers the welder qualification procedure.
WPS – Welding Procedure Specification
WPQ – Welder Performance Qualification
SMAW – Shield Metal Arc Welding
4. RESPONSIBILITIES : Construction Manager / Engineer In-charge / Safety officer / QA QC Engineer
5. TOOLS / EQUIPMENTS
- Arc welding machine.
- Arc welding rod.
- Welding shield & leather gloves.
- Wire Brush
- Hand tools
6. QUALIFICATION OF THE WELDER
Before any production welding is performed, the welders shall be qualified according to the applicable requirement and standard. The welder who satisfactorily complete the procedure qualification test is an acceptance criteria for qualified welders.
7. WELDING PROCEDURE SPECIFICATION
7.1. Welding procedure specification is attached as an attachment.
8. WELDING PROCEDURE
Raise the pipe up to the required location. Position & tighten the pipe support to secure the pipe.
The pipe will be checked for correct level, alignment and position and if necessary, adjusted on the pipe support, or re-level the pipe.
Pipe end shall be chamfered to 45° using the angle grinding machine and groove size will be as per standard and pipe size. Pipe alignment will be maintained by mechanical means or by tack welding which will be melted out during final welding.
Electrode (molted metal) will fill the groove and settle properly. E 7018 class welding electrodes shall be used for root run and subsequently final run.
The welder will use a normal welding transformer to join pipe by tack welding them.
The skilled welders then will start a root weld, and wire brush the root joint so that flux on the joint is completely removed. If necessary grinding will be perform to remove the flux.
After allowing the joint to solidify for a few minutes, The final weld shall be performed and the flux shall be removed once again by wire brushing / grinding
Ensure proper penetration and no undercut during welding of the pipe.
After the end preparation clean the pipe ends and ensure no material and dust are left inside.
Qualified and approved / certified welders shall be engaged in welding works.
Fabricate the structural supports from G.I. angles/ channel as per support schedule as required.
Fix the anchors and threaded rods with hangers/ structural supports as applicable.
Cut the pipes accurately to measurements determined at site.
The valve and pipe are joined with flange welded to the pipe & then tightened together or with valve using nuts and bolts. Proper sealing gasket is inserted between the fittings before tightening
After completion of welding remove the burrs, dirt, and welding slugs and install temporary caps at open end.
Clean the work location.
Welding Procedure Specification
Welder Performance Qualification